DEVELOPMENT AND ASSESSMENT OF ACYCLOVIR MICROSPONGES CONTAINING SUITABLE POLYMERS

The present research was focused on the formulation and evaluation of a microsponge-based topical gel containing Acyclovir to overcome its inherent limitations such as poor oral bioavailability and short biological half-life. The objective was to achieve controlled drug release, thereby enhancing therapeutic efficacy and patient compliance. Acyclovir microsponges were successfully prepared by the quasi-emulsion solvent diffusion method using ethyl cellulose as a polymeric carrier and polyvinyl alcohol (PVA) as a stabilizing agent. The prepared formulations (F1–F4) were subjected to various evaluation parameters including drug–excipient compatibility studies using FTIR, determination of entrapment efficiency, particle size analysis, and in vitro drug release studies. The FTIR spectra revealed no significant chemical interaction between the drug and excipients, confirming their compatibility. Among all the formulations, F4 demonstrated superior performance with the highest entrapment efficiency of 92.6%, maximum drug content, and a sustained drug release of 85.24% over a period of 8 hours. The drug release kinetics of the optimized formulation followed a zero-order model, suggesting a constant release rate independent of drug concentration. Furthermore, the diffusion exponent (‘n’ value) obtained from the Korsmeyer–Peppas model was greater than 0.5, indicating that the drug release mechanism was governed by non-Fickian (anomalous) diffusion involving both diffusion and polymer relaxation processes. These findings conclude that Acyclovir-loaded microsponges incorporated into a topical gel formulation can provide a promising controlled-release system for effective management of herpes simplex infections, with potential advantages in reducing dosing frequency and enhancing patient adherence.